Flap wheel finishing device

ABSTRACT

There is disclosed a finishing wheel formed of an annulus of abrasive flaps. The flaps are of small width, typically about one-fourth to three-fourths inch. This width is not adequate to accommodate the flanges of the flanged end plates or flange discs to which the drive shaft for the wheels are secured if the end plates are mounted in the same way as they are for conventional wide wheels. The length of each flange is greater than one-half the width of the wheel. In one form of the wheel disclosed the slots in the opposite surfaces of the core are displaced radially with respect to each other so that each need be only of sufficient depth to accommodate one flange without penetrating the annulus. In another form of the wheel the flaps are L-shaped and the annulus has an inner flange at the hub. This inner flange engages the flange of a flange disc. An adhesive is deposited on the flange forming the flange and annulus into a rigid structure. The drive shaft is secured between a washer and the flange disc on opposite surfaces of the adhesive.

United States Patent [191 Schaflner, III

[ FLAP WHEEL FINISHING DEVICE [75] Inventor: Gus J. Schaffner, 111, Pittsburgh, Pa.

[73] Assignee: Schaffner Mfg. Co., Inc., Pittsburgh.

221 Filed: June 5, 1972 211 Appl. No.: 259,538

Primary Examiner0thell M. Simpson Attorney, Agent, or Firm-Hymen Diamond m1 3,890,119 1 June 17, 1975 1 1 ABSTRACT There is disclosed a finishing wheel formed of an an nulus of abrasive flaps. The flaps are of small width, typically about one fourth to three-fourths inch. This width is not adequate to accommodate the flanges of the flanged end plates or flange discs to which the drive shaft for the wheels are secured if the end plates are mounted in the same way as they are for conventional wide wheels. The length of each flange is greater than one-half the width of the wheel. In one form of the wheel disclosed the slots in the opposite surfaces of the core are displaced radially with respect to each other so that each need be only of sufflcient depth to accommodate one flange without penetrating the annulus. In another form of the wheel the flaps are L-shaped and the annulus has an inner flange at the hub. This inner flange engages the flange of a flange disc. An adhesive is deposited on the flange forming the flange and annulus into a rigid structure. The drive shaft is secured between a washer and the flange disc on opposite surfaces of the adhesive.

6 Claims, 8 Drawing Figures 1 FLAP WHEEL FINISHING DEVICE BACKGROUND OF THE INVENTION This invention relates to the art of finishing materials such as metal, wood or plastic and has particular relationship to finishing wheels formed of an annulus of flaps. As used in this application the word finishing includes within its scope polishing, in whose practice there may be substantial removal of material, as well as buffing and coloring, in whose practice a sheen is imparted without substantial removal of material. The flaps may be structured to meet the respective purposes of the wheels. In some cases the flaps may be composed throughout of non-abrasive fabric. Typically, however, the flaps are of woven fabric abrasive on one surface and smooth on the opposite surface. There are also wheels whose flaps are abrasive on both surfaces and wheels in which abrasive and non-abrasive flaps or abrasive flaps of different grit size are interleaved or in which flaps of woven and non-woven fabric are interleaved, as disclosed in US. Pat. No. 3,706,167 granted Dec. 19, 1972 to Robert D. Schaffner for Finishing Apparatus. There are also wheels whose flaps are all of non-woven abrasive fabric.

The annulus of flaps has a core of hub at the center formed by bonding or securing together the radially inner ends of the flaps. The flaps extend freely from this core.

During a finishing operation a finishing wheel is rotated at a high speed with the free ends of its flaps in contact with the work. For driving the wheel, end plates or flange discs are typically centrally disposed in engagement with the core of the annulus and a drive shaft which passes through a bearing in the end plates is secured by nuts to the end plates. (See, for example, end plates 91 and 93 FIG. 8 Schaffner US. Pat. No. 3,294,502). The end plates are provided with projections or flanges which engage circular slots in opposite core or hub surfaces of the annulus. Typically, the flanges penetrate to a depth of about one-fourth inch or more into the core.

This invention concerns itself with wheels having narrow flaps; typically flaps having a width of about onefourth or one-half inch and in some cases as high as three-fourths or one inch. Typically such wheels are used in grinding the titanium blades of jet engines. In grinding such blades it is desirable that a blade be held during grinding so that it extends towards the hub or axis of the wheel. It is then necessary that obstruction to the blade be avoided and that the hub of the annulus project from the opposite surfaces of the annulus as little as practicable.

It is necessary that the annulus ofa wheel whose flaps are narrow be adapted to accommodate the flanges of the flange disc to achieve this purpose, the flaps of wheels, whose flaps are narrow, are, in accordance with the teachings of the prior art, T-shaped with the head of the T at the core, and of substantial radial length and width. When such flapsare formed into an annulus, the annulus has a hub or core which protrudes from both opposite surfaces of the wheel. Typically, the head of the T may have a length of one-inch and a width of about one-inch and for such flaps, a hub one-inch in radial length and one-quarter inch in height on each side protrudes centrally from the annulus.

This prior-art practice results in a substantial cost in material. A typical finishing wheel may have onethousand or more flaps which are formed of costly material. The additional material used to form the heads of the Ts of the flaps imposes a substantial increment in the cost of the flaps. In addition, the protruding hub militates against effective processing of work pieces, such as the titanium blades of jet engines, which are held, during finishing. so that they extend towards the hub.

It is an object ofthis invention to overcome the disadvantages of the prior art and to provide a finishing wheel formed of an annulus of flaps whose cost shall be minimized by elimination of the necessity for T-shaped flaps and in whose use obstruction to work pieces. extending inwardly towards the axis of the wheel, shall be minimized.

SUMMARY OF THE INVENTION In accordance with this invention, there is provided a finishing wheel formed of an annulus of narrow flaps having, in the opposite surfaces of its core or hub, slots for the flanges of flange discs, which are radially displaced with reference to each other. The slots can ac commodate flanges extending into the annulus a distance equal to half or even a greater fraction of the width of the flaps. The annulus is formed of flaps in the form of elongated rectangles having, near their ends, grooves displaced along the length with respect to each other. When such a wheel is in use there are not protruding hub parts to interfere with the ends of work pieces. This aspect of the invention is applicable to wheels of greater width than one-fourth inch.

In accordance with a further aspect of this invention, particularly applicable where the flaps are very narrow, typically about one-fourth inch or even less, the annulus extends from a hub of adhesive deposited in a dishshaped end plate or flange disc. The adhesive is bonded to the core of the annulus. In this case the flaps are generally L-shaped with the feet of the L forming a flange protruding from one surface. This flange engages the flange of the disc. A flanged washer is disposed in the face of the adhesive opposite the disc. The shaft of the drive for the wheel is held by nuts which engage the disc on one side and the washer on the opposite side.

BRIEF DESCRIPTION OF THE DRAWING For a better understanding of this invention, both as to its organization and as to its method of operation, together with additional objects and advantages thereof, reference is made to the following description, taken in connection with the accompanying drawing, in which:

FIG. I is a plan view of a finishing wheel in accordance with this invention;

FIG. 2 is a view in section taken along line IIII of FIG. 1;

FIG. 3 is a fragmental view of a flap of the wheel of FIG. 1',

FIG. 4 is a fragmental view of a section of the annulus of a wheel as shown in FIG. 1 demonstrating the manner in which the core or hub is formed;

FIG. 5 is a plan view of a finishing wheel in accordance with a modification of this invention;

FIG. 6 is a view in section taken along line VI-VI of FIG. 5;

FIG. 7 is a fragmental view ofa flap used in the wheel of FIG. 5; and

FIG. 8 is a fragmental view of a section of the annulus ofthe wheel shown in FIG. demonstrating the manner in which the core or hub is made.

DETAILED DESCRIPTION OF THE INVENTION The apparatus shown in FIGS. 1 through 4 is a finishing wheel 11 having an annulus 13 of flaps 15 and flange discs or end plates 17 and 19 whose flanges 21 and 23 engage circular slots 25 and 27 respectively in the hub 29 of the annulus. The flap 15 has grooves 31 and 33 which form slots 25 and 27 respectively when the flaps 15 are formed into an annulus. The grooves 31 and 33 are near the one end of the flap 15 which is disposed at the center of the annulus. The slots 25 and 27 are then radially displaced with respect to each other, the slot 27 being nearer the periphery than the slot 25. The flanges 21 and 23 are near the peripheries of the respective discs 21 and 23 so that disc 21 has a smaller diameter than disc 23. However, the discs may be of equal diameter with the flange which engages the slot 25 at a smaller distance from the center of its disc than the flange which engages slot 27. As shown in FIG. 2. the flange discs 17 and 19 are flush with the surfaces of the wheel 11.

In forming the annulus the flaps 15 are disposed on a projection such as the flange 21 of disc 17 so that they extend radially side by side from this flange 21. After an annulus is formed, the flaps in one region are forced apart, and more flaps are inserted until the annulus is tight. After the annulus is formed an adhesive 41 (FIG. 4) typically, an epoxy resin with a suitable hardener, is painted on the inner periphery of the annulus and the part of the annulus extending from the periphery and including. and extending just beyond, the slot 27. The adhesive 41 is distributed over the inside of the slot. The annulus is then turned over and the adhesive 41 is painted over the part of the annulus extending just be yond the slot 25. The viscosity of the adhesive is set so that the adhesive penetrates (by capillarity) between the flaps 15. The slots 25 and 27 are then coated with silicone rubber 43. The flange discs 17 and 19 are then mounted on the annulus with their flanges 21 and 23 engaging, and secured by the silicone rubber to, the slots 25 and 27 and the adhesive 41 is cured to form the annulus 13 with a solid core.

The disc 19 has a central cylindrical shell 45 which serves as a bearing for the drive shaft (not shown). Typically. the shell 45 passes through the opening in disc 17. The drive shaft (not shown) is secured by nuts (not shown) which are screwed onto the shaft and engage the discs 25 and 27. Lock washers (not shown) may be inserted between the nuts and the discs 25 and 27.

In some situations the shell 45 may be omitted. In this case both discs have holes ofthe same diameter and the shaft (not shown) is supported on the edges bounding the holes. To assure that the shaft is aligned, the wheels of this type are cured on a CALROD heater of outside diameter such as to permit the wheel to be slipped over and aligned.

The apparatus shown in FIGS. 5 through Sis a finishing wheel 51 including an annulus 53 of flaps 55. The flaps 55 are of generally L-shape each flap having a foot 57. The annulus formed of the flaps 55 has, extending from one surface of, its hub or core a projection or flange 59 formed of the foot 57 of the L.

The wheel 51 includes a generally dish-shaped flange disc 61 having a flange 63. A cylindrical shell 65 extends from the center of disc 61 and serves as hearing for a drive shaft (not shown). A flange washer 67 is supported on the center of disc 61 with the stem 69 of the washer 67 extending over the shell 65. The disc 61 contains a hub 71 of cured adhesive, typically an epoxy resin with a suitable hardener. The annulus 53, the disc 61 and the washer 67 are secured together into a rigid unit by the adhesive 71 with the flange 59 in engagement with the flange 63. The drive shaft (not shown) is secured by nuts (not shown) which engage the disc 61 and the flange 73 of the washer 67. The pressure on the washer 67 by the nut is distributed over the surface of the washer and prevents the adhesive 71 from being crushed.

In forming the annulus 53 the disc 61 is placed on a surface with its flange 63 upwardly. The flaps 55 are arranged side-by-side radially with their feet 57 engaging the flange 63 internally. When an annulus is formed, the flaps 55 are forced apart in one region and additional flaps 55 inserted until the annulus 53 is tight. The inner periphery and the surface opposite the flange 59 are then painted with an adhesive 81 (FIG. 8). typically an epoxy resin with a suitable hardener; the surface being painted to a distance just beyond the outer pe riphery of the flange 59. The annulus is then turned over and the circular strip defined by the end of the foot and the inner periphery of the flange 59 are painted with an adhesive. The adhesive has a viscosity such that it penetrates by capillarity between the flaps 55. Silicone rubber 83 is then deposited along the outer corners (the instep) of the core.

The annulus 53 is now placed on the disc 61 with its flange 59 engaging the flange 63. The washer 67 is slipped over the shell 65 and adhesive is poured on the disc, and the adhesive between the flaps 55 ofthe annulus 53 and the poured adhesive 71 are cured to form a core in the annulus 53 and the hub 71. The adhesive 71 is essentially cast into a mold formed by the disc 61, the washer 67 and the annulus 53.

While preferred embodiments of this invention have been disclosed herein. many modifications thereof are feasible. This invention then is not to be restricted except insofar as is necessitated by the spirit of the prior art.

I claim:

1. Finishing apparatus including an annulus of flaps of relatively small width, the flaps of said annulus being bonded near the center of said annulus to form a central core, said flaps extending freely from said core, the said core having slots penetrating into the opposite surfaces thereof and extending generally coaxial with said annulus, the said annulus to accommodate flange discs on opposite surfaces of said annulus extending over said core generally coaxially with said annulus with the flanges of said discs engaging said slots. the sum of the widths of said flanges being such that if the flanges were coextensive they could not be accommodated by the width of said flaps, the said apparatus being characterized by that a said slot extending into one surface is displaced radially with respect to the corresponding slots extending into the opposite surface so that no pair of slots extending into opposite surfaces of said core are coextensive.

2. The apparatus of claim 1 wherein the sum of the depths of the slots is approximately equal to the width of the flaps.

3. Finishing apparatus including an annulus of flaps of relatively small width, said flaps being bonded near the center of said annulus to form a central core with said flaps extending freely from said core, the said core having slots penetrating into the opposite surfaces thereof and extending generally coaxial with said annulus, a slot extending into one surface of said core being displaced radially with respect to a corresponding slot extending into the opposite surface of said core so that there are not slots extending into opposite surfaces of said core which are coextensive with each other, and a pair of flange discs disposed coaxial with the annulus at the opening thereof, each disc having a flange for engagement in a said slot of said core, one of said flange discs being positioned with its flange engaging the slot in one surface of said core and the other of said flange discs being positioned with its flange engaging the slot in the opposite surface of said core.

4. The apparatus of claim 1 wherein there is only one slot extending into each surface of the annulus.

5. The apparatus of claim 3 wherein the flanges of the flange discs extend around the peripheries of said discs, the diameters of said flange discs being different in dependance upon the radial displacement of the slots.

6. The apparatus of claim 3 wherein one of the flange discs supports a central cylindrical hub and the other flange disc has a central opening through which the hub passes. 

1. Finishing apparatus including an annulus of flaps of relatively small width, the flaps of said annulus being bonded near the center of said annulus to form a central core, said flaps extending freely from said core, the said core having slots penetrating into the opposite surfaces thereof and extending generally coaxial with said annulus, the said annulus to accommodate flange discs on opposite surfaces of said annulus extending over said core generally coaxially with said annulus with the flanges of said discs engaging said slots, the sum of the widths of said flanges being such that if the flanges were coextensive they could not be accommodated by the width of said flaps, the said apparatus being characterized by that a said slot extending into one surface is displaced radially with respect to the corresponding slots extending into the opposite surface so that no pair of slots extending into opposite surfaces of said core are coextensive.
 2. The apparatus of claim 1 wherein the sum of the depths of the slots is approximately equal to the width of the flaps.
 3. Finishing apparatus including an annulus of flaps of relatively small width, said flaps being bonded near the center of said annulus to form a central core with said flaps extending freely from said core, the said core having slots penetrating into the opposite surfaces thereof and extending generally coaxial with said annulus, a slot extending into one surface of said core being displaced radially with respect to a corresponding slot extending into the opposite surface of said core so that there are not slots extending into opposite surfaces of said core which are coextensive with each other, and a pair of flange discs disposed coaxial with the annulus at the opening thereof, each disc having a flange for engagement in a said slot of said core, one of said flange discs being positioned with its flange engaging the slot in one surface of said core and the other of said flange discs being positioned with its flange engaging the slot in the opposite surface of said core.
 4. The apparatus of claim 1 wherein there is only one slot Extending into each surface of the annulus.
 5. The apparatus of claim 3 wherein the flanges of the flange discs extend around the peripheries of said discs, the diameters of said flange discs being different in dependance upon the radial displacement of the slots.
 6. The apparatus of claim 3 wherein one of the flange discs supports a central cylindrical hub and the other flange disc has a central opening through which the hub passes. 